Chapter 2: Neurons & Glia Flashcards
What is the approximate number of neurons and glia in the adult human brain?
Roughly 85 billion of each type
What are the main functions of neurons in the brain?
Sensing changes in the environment, communicating these changes to other neurons, and commanding the body’s responses.
Describe the neuron doctrine and its credited individual.
The neuron doctrine states that the nervous system is made up of discrete individual cells, credited to Santiago Ramón y Cajal.
What does a Golgi stain reveal that a Nissl stain does not?
The entire morphology of neurons, including the cell body, dendrites, and axons.
List three physical characteristics that distinguish axons from dendrites.
Branching pattern, length, and uniformity.
Which structures are unique to neurons?
Synaptic vesicles
Describe the steps from DNA in the nucleus to synthesis of a membrane-associated protein molecule.
Transcription, RNA processing, Translation, Protein modification and transport
What effect would colchicine have on anterograde transport and the axon terminal?
It would halt anterograde transport, leading to impaired synaptic transmission and membrane maintenance.
Classify the cortical pyramidal cell based on the number of neurites, presence of dendritic spines, connections, and axon length.
Multipolar, spiny, projection neurons, with long axons.
How can genetic information be used to study a specific category of neuron?
Using reporter genes like GFP to identify and study neurons expressing unique genes.
What is myelin, its function, and the cells providing it in the CNS?
Myelin is an insulating layer that increases the speed of electrical impulses, provided by oligodendrocytes in the CNS.
What are the main parts of a neuron?
Cell body (soma), dendrites, and axon.
What is the function of the dendrites?
Receive signals from other neurons and convey them towards the cell body.
Describe the role of the axon in a neuron.
Transmits electrical impulses away from the neuron’s cell body to other neurons or to muscles or glands.
What is the axon hillock and its significance?
The axon hillock is a specialized part of the cell body from which the axon originates; it plays a crucial role in initiating nerve signals.
Explain the myelin sheath and its function.
The myelin sheath is a fatty layer that covers the axon of some neurons, speeding up the transmission of electrical signals along the axon.
What are nodes of Ranvier and their function?
Gaps in the myelin sheath along the axon, which facilitate rapid signal transmission by allowing ions to flow in and out of the neuron.
Define the term ‘synapse’.
A junction between two neurons or between a neuron and a muscle/gland, where signals are transmitted from one cell to the other.
What is the importance of the cell body (soma) in a neuron?
Contains the neuron’s nucleus and organelles, responsible for metabolic activities and integrating incoming signals.
What is the role of glial cells in relation to neurons?
Support neurons structurally, nutritionally, and in many other ways, including insulating axons with myelin and maintaining the extracellular environment.
